Dielectric resonator antenna arrays

Abstract

Arrays of low permittivity Polymer-based Resonator Antenna elements with different configurations. Individual array elements can be fabricated with complicated geometries; these elements can be assembled into complicated patterns as a single monolithic fabricated structure using narrow wall connecting structures, which removes the requirement to position and assemble the array elements. Monolithic array structures can be assembled as sub-arrays in larger array structures. Elements, sub-arrays, and arrays can also be formed by inserting dielectric materials into cavities defining their lateral geometries, and fabricated in polymer templates. The polymer templates can be removed or retained to function as part of the antenna. Effective excitation is achieved by one of a number of coupling methods, including standing metal strip feeding on the vertical sides of the elements, feeding by tall metal transmission lines in contact or in close proximity to the vertical sides of the elements, modified microstrip feeding, or aperture feeding by using a slot in the metal plane underneath the elements. The wideband array feeds are realized by optimized transmission line distribution networks which include wideband matching sections.

We claim: 
     
       1. A dielectric resonator antenna array comprising:
 a substrate with a first planar surface; 
 a template with a top surface and a bottom surface opposite the top surface, the bottom surface of the template disposed on the first planar surface of the substrate, the template defining a plurality of cavities extending from the bottom surface toward the top surface and substantially through the template; 
 a plurality of dielectric resonator bodies, embedded respectively within the plurality of cavities of the template, and disposed on the first planar surface of the substrate, wherein each of the resonator bodies is spaced apart from each other, wherein each of the resonator bodies has a relative permittivity in the range between 2 and 12; 
 a plurality of coupling structures, each of the coupling structures operatively coupled to a respective one of the resonator bodies to provide an excitation signal thereto; and 
 a signal distribution structure operatively coupled to the plurality of coupling structures to provide the excitation signal thereto. 
 
     
     
       2. The dielectric resonator antenna array of  claim 1 , wherein the signal distribution structure comprises a plurality of feedlines, each of the feedlines operatively coupled to at least one of the coupling structures. 
     
     
       3. The dielectric resonator antenna array of  claim 1 , wherein the signal distribution structure further comprises at least one transmission line. 
     
     
       4. The dielectric resonator antenna array of  claim 1 , wherein each of the resonator bodies is connected to at least one other of the resonator bodies via a wall structure. 
     
     
       5. The dielectric resonator antenna array of  claim 4 , wherein the resonator bodies form a single monolithic structure. 
     
     
       6. The dielectric resonator antenna array of  claim 4 , wherein the resonator bodies form an array of sub-arrays, wherein the sub-arrays are formed as separate monolithic structures. 
     
     
       7. The dielectric resonator antenna array of  claim 3 , wherein the at least one transmission line is a thick metal transmission line that has a metal thickness between 10% and 100% of a thickness of the plurality of resonator bodies. 
     
     
       8. The dielectric resonator antenna array of  claim 1 , wherein each of the plurality of coupling structures is provided under a respective resonator body in proximity to and substantially parallel to the planar surface. 
     
     
       9. The dielectric resonator antenna array of  claim 1 , wherein each of the plurality of coupling structures is a tapered respective section of the signal distribution structure. 
     
     
       10. The dielectric resonator antenna array of  claim 1 , wherein each of the plurality of coupling structures is provided by a slot defined in the planar surface beneath a respective resonator body. 
     
     
       11. The dielectric resonator antenna array of  claim 1 , wherein each of the plurality of coupling structures terminates in proximity to a respective resonator body substantially perpendicularly to the planar surface. 
     
     
       12. The dielectric resonator antenna array of  claim 11 , wherein each of the plurality of coupling structures has a height between 10% and 100% of the respective resonator bodies. 
     
     
       13. The dielectric resonator antenna array of  claim 1 , wherein each of the plurality of coupling structures is embedded within a respective resonator body substantially perpendicularly to the planar surface. 
     
     
       14. The dielectric resonator antenna array of  claim 1 , wherein each of the feedlines is a tee-line that branches off at least one main feedline. 
     
     
       15. The dielectric resonator antenna array of  claim 1 , wherein the signal distribution structure is periodically loaded by the plurality of resonator bodies. 
     
     
       16. The dielectric resonator antenna array of  claim 1 , wherein the dielectric resonator bodies are formed of polymer-based materials. 
     
     
       17. A method of fabricating a dielectric resonator antenna array, the method comprising:
 providing a substrate with at least a first planar surface; 
 providing a template with a top surface and a bottom surface opposite the top surface, the bottom surface of the template disposed on the first planar surface of the substrate; 
 defining a plurality of cavities in the template, each of the plurality of cavities extending from the bottom surface toward the top surface and substantially through the template; 
 embedding a plurality of polymer-based resonator bodies within the plurality of cavities of the template and on the first planar surface, wherein each of the bodies is spaced apart from each other, wherein each of the resonator bodies has a relative permittivity in the range between 2 and 12; 
 providing a plurality of feed coupling structures on the first planar surface, each of the coupling structures positioned to operatively couple to a respective one of the resonator bodies to provide an excitation signal thereto; and 
 providing a signal distribution structure to operatively couple to the plurality of coupling structures to provide the excitation signal thereto. 
 
     
     
       18. The method of  claim 17 , wherein at least one of the plurality of resonator bodies is coupled to at least one other of the resonator bodies by a wall structure. 
     
     
       19. The method of  claim 17 , wherein the template is provided by
 depositing at least one polymer-based material; 
 exposing the at least one polymer-based material to a lithographic source via a pattern mask, wherein the pattern mask defines each of the plurality of cavities; 
 developing a portion of the at least one polymer-based material; 
 removing one of an exposed portion and an unexposed portion of the at least one polymer-based material to reveal the plurality of cavities, and 
 wherein the plurality of polymer-based resonator bodies are embedded by filling the plurality of cavities with at least one other of the at least one polymer-based material to form the respective polymer-based resonator bodies. 
 
     
     
       20. The method of  claim 17 , wherein the dielectric resonator bodies are formed of polymer-based materials. 
     
     
       21. A method of fabricating a dielectric resonator antenna array, the method comprising:
 providing a substrate with at least a first planar surface; 
 providing a mold that is retained on the substrate, the mold defining a plurality of cavities shaped to define a plurality of resonator bodies disposed on the first planar surface, wherein each of the cavities is spaced apart from each other; 
 filling the plurality of cavities with a first dielectric material to form the resonator bodies, wherein the first dielectric material has a relative permittivity in the range between 2 and 12; 
 providing a plurality of feed coupling structures on the first planar surface, each of the coupling structures positioned to operatively couple to a respective one of the resonator bodies to provide an excitation signal thereto; and 
 providing a signal distribution structure to operatively couple to the plurality of coupling structures to provide the excitation signal thereto. 
 
     
     
       22. The method of  claim 21 , wherein the mold further defines at least one coupling cavity shaped to define the plurality of feed coupling structures, and wherein the plurality of feed coupling structures are provided by depositing a conductive material within the at least one coupling cavity. 
     
     
       23. The method of  claim 21 , wherein the mold further defines at least one distribution cavity shaped to define the signal distribution structure, and wherein the signal distribution structure is deposited within the at least one distribution cavity. 
     
     
       24. The method of  claim 21 , wherein the mold is defined by lithography. 
     
     
       25. The method of  claim 21 , further comprising, prior to providing the mold, initially providing the mold on a sacrificial substrate, wherein the cavities are filled on the sacrificial substrate, further comprising removing the mold and the resonator bodies from the sacrificial substrate, and transferring the mold and the resonator bodies to the first planar surface. 
     
     
       26. The method of  claim 21 , wherein the dielectric resonator bodies are formed of polymer-based materials. 
     
     
       27. The method of  claim 21 , wherein the mold has a plurality of layers, the layers formed by repeating the forming, the exposing, the developing and the removing at least once.